LR turning white

[jasper180]

30 gal tank has been cycling for week and a half now. The purple growth on the rock is turning white over the last day and 1/2. Nitrates are 0, Amonia is close to 0, Nitrites are about .75 ppm and Ph is high at 8.6. Have been doing 4-5 gal water changes every two days to lower PH. Have not check PH since water change yesterday. Plan on checking it tonight. What is the white growth.
Erik

 

[steamboat1569]

Sounds like bleaching. Your coraline algea is dying off. Check the water temp. If it is high, this will cause it. I had mine do this, but it was due to low calcium.
In my own oppinion, it is to early in your cycle to be doing water changes. This will slow the cycling down considerably. Let it cycle normally. You want your test readings to go up, and then level off.